I have developed some nice epoxy based AP propellants. I've used both HTPB
and epoxy and much prefer the latter for a number of reasons. It took a lot
of development work to get epoxy to work as a suitable binder (porosity was
a big issue). The issues were overcome and I have static tested and flown
many rockets powered by these epoxy-AP propellants, very reliable (HTPB
motors sometimes cato'ed for no apparent reason). Someday I'll document my
work.
R.
On Fri, Mar 29, 2024 at 10:14 AM Azadul Haq <azadulhaq@xxxxxxxxx> wrote:
Thanks. By bonding agents I meant epoxy to mix with APCP. I had tried
different brands but not getting good results.
Sincerely,
Azadul Haq
On Fri, Mar 29, 2024 at 10:09 AM Richard Nakka <richard.rocketry@xxxxxxxxx>
wrote:
Actually, this forum has been opened up (as of recently) for discussion
of all forms of propellant, not solely sugar. Regarding your question, I do
not use a bonding agent, could you elaborate on your issues?
R.
On Fri, Mar 29, 2024 at 10:06 AM Azadul Haq <azadulhaq@xxxxxxxxx> wrote:
I know this forum is for Sugar based propellant. But I have a question
about APCP. I have not been successful in getting good performance at all.
What bonding agents are you using for your APCP that gives good results?
Sincerely,
Azadul Haq
On Fri, Mar 29, 2024 at 8:42 AM Tr Mu <tl01001101@xxxxxxxxx> wrote:
My main reason for not wanting to go to dextrose is the viscosity.
Sorbitol is quite thin and thus I can load it up pretty high with KNO3, Mg,
& other things. My current formula for a fast propellant is only 30%
sorbitol and still can pour easily into my 29mm casting setup (with coring
rod already in place). Paraffin was a thought because it is even thinner
when melted and I was hoping it would allow me to go higher on the KNO3
percentage. This is why I started up in the 80%s. Mainly I'm looking for
things that are different to do. Eventually I'll be able to do APCP and get
all of the performance I want, but for now it is fun to see how much I can
get out of cheaper ingredients.
Trevor
On Thu, Mar 28, 2024 at 11:07 PM Lincoln Ross <lr21643@xxxxxxxxx>
wrote:
BTW, Trevor, if you're trying to save money, you might consider
dextrose. I think Baker's Authority has it at something like $79 for 50
lbs. As usual, Richard Nakka has quite a bit of info about using it in
fuel
grains: https://www.nakka-rocketry.net/dex.html Note that the
hydrated form melts at a low temperature and doesn't give up all that much
specific impulse.
On Thu, Mar 28, 2024 at 8:21 PM Lincoln Ross <lr21643@xxxxxxxxx>
wrote:
There is also something called Gulfwax, commonly found at
supermarkets. I think mine might be from the previous millennium, though.
Unless there was some kind of aging over that time, I bet it is about the
same stuff. In bulk, of course, the stuff is cheaper.
On Thu, Mar 28, 2024 at 5:36 AM Tr Mu <tl01001101@xxxxxxxxx> wrote:
I just used some I found at Hobby Lobby. It was labeled as being
pure paraffin for candle making.
Trevor
On Thu, Mar 28, 2024, 12:56 AM Lincoln Ross <lr21643@xxxxxxxxx>
wrote:
Any specifics or does the paraffin just end up covered with tiny
bite marks? ;-)
On Thu, Mar 28, 2024 at 12:53 AM Bruce Beck <bbeck7@xxxxxxxxx>
wrote:
Nitrates are lousy oxidizers for paraffin.AP works well but chuffs
at low pressure.
On Wed, Mar 27, 2024 at 4:16 PM Tr Mu <tl01001101@xxxxxxxxx>
wrote:
This past weekend I had the idea of trying a paraffin based
propellant. Has anyone tried this? It melts at a lower temp than
sorbitol
and based on the prices I found, it would end up cheaper than my
current
sorbitol motors.
I tried some small 10 gram batches of 80:20, 85:15, & 90:10
KNO3:paraffin. These were based around 85:15 being an "ideal" ratio
as per
ProPep3 None of them would sustain combustion. I want to try it
again this
weekend with finer ground KNO3, but I wanted to see if anyone else
has
tried it.
Trevor
